[QPSI] a MAPLE package for the determination of quasi-polynomial symmetries and invariants of ODEs system. T.M. Rocha Filho, A. Figueiredo, L. Brenig.

PROGRAM SUMMARY
Title of program: QPSI
Catalogue identifier: ADJX
Ref. in CPC: 117(1999)263
Distribution format: uuencoded compressed tar file
Operating system: UNIX, WINDOWS/95
Number of bits in a word: 32
Number of lines in distributed program, including test data, etc: 3043
Programming language used: Maple

Nature of physical problem:
The search of invariant tensors and invariants for dynamical systems.

Method of solution
The algorithm to calculate a quasi-polynomial invariant tensor field for a quasi-polynomial dynamical system is described in [1,2].

Restrictions on the complexity of the problem
The time consuming becomes higher when the order of the semi-invariant increases.

Typical running time
Depends strongly on the order and the complexity of the ODE's system.

Unusual features of the program
QPSI is the first MAPLE program that calculates quasi-polynomial invariant tensor fields for ODE's systems in the quasi-polynomial form (including the scalar invariant).

References

 [1] A. Figueiredo, T.M. Rocha Filho, L. Brenig, "Algebraic structures   
     and invariants of differential systems", accepted for publication in
     J. Math. Phys. (1997).                                              
 [2] A. Figueiredo, T.M. Rocha Filho, L. Brenig, "Necessary conditions   
     for the existence of quasi-polynomial invariants: the quasi-        
     polynomial and Lotka-Volterra systems", submitted in Physica A      
     (1997).